Various organic phosphates having pesticidal activities are known. For instance, U.S. Pat. No. 3,839,511 discloses O-ethyl-S-n-propyl-O-(substituted-phenyl)phosphorothiolates represented by the following formula and their pesticidal activities: ##STR2## where X is halogen, lower alkyl, nitro, cyano, lower alkylmercapto, lower alkylsulfinyl or lower alkoxycarbonyl, and m is 1 to 3.
However, a phosphate or thiophosphate of benzofuranol has not been known.
On the other hand, in recent years, it has become difficult to control pests by conventional pesticides because the pests have acquired resistance through the extensive use of the pesticides for many years. Under these circumstances, it is desired to develop a new pesticide having a high pesticidal activity and a low phytotoxicity.